Add Sawtooth Generator Block

rtl/genSaw.sv

@@ -0,0 +1,39 @@
+`default_nettype none
+
+module genSaw
+( input  var        i_clk48
+, input  var        i_rst48_n
+, input  var        i_pause
+, input  var [23:0] i_tf
+, output var [47:0] o_lr
+, output var        o_new_pulse
+);
+
+logic [8:0] clk_div;
+always_ff @(posedge i_clk48)
+  if (!i_rst48_n)             clk_div <= 0;
+  else if (clk_div == 9'd500) clk_div <= 0;
+  else                        clk_div <= clk_div + 1;
+
+logic clk_48k;
+always_ff @(posedge i_clk48)
+  if (!i_rst48_n)             clk_48k <= 0;
+  else if (clk_div == 9'd500) clk_48k <= ~clk_48k;
+
+logic clk_48k_past;
+always_ff @(posedge i_clk48)
+  clk_48k_past <= clk_48k;
+
+assign o_new_pulse = clk_48k && !clk_48k_past;
+
+logic [23:0] saw_step;
+assign saw_step = (24'd699 * i_tf) >> 1;
+
+logic [23:0] waveform;
+always_ff @(posedge clk_48k)
+  if (!i_rst48_n)    waveform <= '0;
+  else if (!i_pause) waveform <= waveform + saw_step;
+
+assign o_lr = {waveform, waveform};
+
+endmodule